A conventional pneumatic bubble generating device is generally connected with a high pressure spray gun and the detergent is transformed into mist which is sucked into the bubble generating device. The bubble generating device includes sponges or non-woven fabrics which include multiple orifices and the detergent passes through the sponges or non-woven fabrics to generate the bubbles which are then sprayed by high pressure and attached on the objects to be cleaned.
However, the generation of the bubbles is not satisfied because the orifices are arranged randomly and the broken bubbles and the mist leave significant detergent in the orifices, and the detergent flows between the orifices and form a bubble-like film with other detergent in other orifices. The film is blown into bubbles which are lighter than the air so that the bubbles are delivered to a far distance. Some detergent is sprayed by the high pressure air stream and forms tiny bubbles which have smaller surface which cannot be attached with other bubbles to form large bubbles. The small bubbles are easily vaporized and broken so that they cannot be attached on the objects to be cleaned.
The sponges or non-woven fabrics with multiple orifices tend to be deformed by the impact form the high pressure streams and the deformed sponges or non-woven fabrics make the orifices to be uneven which affect the flow of the air and the detergent. Besides, the sponges or non-woven fabrics are easily rotten and cannot be cleaned. The sponges or non-woven fabrics are gradually sheared into pieces which cannot generate sufficient bubbles.
The sponges or non-woven fabrics have limited time of life and it is inconvenient for the users to clean them regularly.
In order to prevent leakage, the sponges or non-woven fabrics are glued and different to disassemble from the body. Once the sponges or non-woven fabrics are disassembled from the body of the spray gun, leakage is almost not avoided.
The present invention intends to provide a bubble generating device which improves the shortcomings of the conventional devices.